Subtropical Storm Beryl forms

The second named storm of this unusually fast-starting 2012 Atlantic hurricane season is here. Subtropical Storm Beryl formed Friday night, a few hundred miles east of the South Carolina coast, from an area of disturbed weather that had moved from the Western Caribbean northeastward. Beryl's formation marks the first time since the hurricane season of 1908 that two Atlantic named storms have formed so early in the year. The only other year with two storms so early in the year was 1887. Records of tropical cyclones in the Atlantic extend back to 1851.

Figure 1. Morning satellite image of Beryl.

The clockwise flow of air around an extremely intense ridge of high pressure that is bringing record heat to the Midwest this weekend is currently driving Beryl to the southwest, and this motion is likely continue until Beryl is very close to the Georgia/Northern Florida coast on Sunday night. As I explain in my Subtropical Storm Tutorial, a subtropical storm typically has a large, cloud free center of circulation, with very heavy thunderstorm activity in a band removed at least 100 miles from the center. The difference between a subtropical storm and a tropical storm is not that important as far as the winds they can generate, but tropical storms generate more rain. A key difference between tropical and subtropical storms is that tropical systems have the potential to quickly grow into hurricanes, while subtropical storms do not. Thus, we need not be concerned about Beryl intensifying to hurricane strength while it is still subtropical. If the storm manages to build a large amount of heavy thunderstorms near its center, these thunderstorms should be able to add enough heat and moisture to the atmosphere to turn Beryl into a tropical storm. This process will be aided as Beryl passes over the warmest waters of the Gulf Stream Saturday night and Sunday morning. But as Beryl makes its likely transition to a tropical storm on Sunday afternoon and evening as it approaches the coast, the storm will move off of the warmest Gulf Stream waters into waters that are cooler (25°, 77°F), and with with lower total heat content. This will limit the storm's potential to strengthen. The 11 am Saturday wind probability advisory from NHC gave Beryl just an 8% chance of becoming a hurricane. There is a lot of dry air surrounding Beryl, thanks to an upper-level low pressure system aloft, and this will keep rainfall amounts much lower that what we would expect if Beryl was a tropical storm. Thus, flooding due to heavy rains is probably not a huge concern with this storm, particularly since the Southeast U.S. coast is under moderate to extreme drought. The 2 - 4 inches of rain expected from Beryl will not be enough to bust the drought, since the Southeast U.S. is generally suffering a rainfall deficit of 8 - 12 inches (since October 1.) Heavy rains from Beryl are not likely to begin affecting coastal South Carolina, Georgia, and Northern Florida until Sunday.

Figure 2. Moderate to exceptional drought is currently gripping the Southeast U.S.; Beryl's rains would be welcome. Image credit: U.S. Department of Agriculture.

Bud hits Mexico and dissipatesHurricane Bud hit Mexico as a tropical depression early this morning, and has now dissipated, thanks to dry air, wind shear, and interaction with Mexico's mountainous terrain. As Bud approached Mexico on Friday, it brought tropical storm-force winds and heavy rains to the coast. Winds at Manzanillo peaked at 41 mph, with a gust to 55 mph, Friday afternoon. Thursday night at 11 pm EDT, Bud peaked at Category 3 status, with 115 mph winds, becoming the earliest Category 3 hurricane on record so early in the year in the Eastern Pacific. There are no reports of deaths or damage from Bud so far, and with only another inch or so of rain expected from the storm, Mexico appears to have escaped serious damage.

Figure 3. True-color satellite image of Hurricane Bud taken by NASA's Terra satellite at 1:15 pm EDT May 25, 2012. At the time, Bud was a Category 1 hurricane with 85 mph winds. Image credit: NASA.

Quoting hurricanehunter27:A lot of the convection is starting to fall apart on the West side. Needs to refire soon.

Cutting off the dry air will fill in the ULL rather quickly. The surface low will need to generate it's own convection once that process is complete. I for one am wondering if it is possible, we'll see.

Um actually I think they goofed up a bit there, its still ENE of Jacksonville, but if it keeps moving SW it will be East of Jacksonville by early tomorrow morning, which means it would have to move WNW before landfall to get to their landfall point

Nice stuff. FSU sounds awesome to me but I will probably try to stay in-state for cheaper tuition. GA Tech seems like the best in-state option (if you're in GA of course) for an atmospheric/physical/space science degree, even though its main attraction is its engineering program.

my brother wants to go there next year to study meteorology, his handle is TheOnlyBravesFan with the stupid girl evony picture, but he hates Wunderground.

Seems like the convection on the west side of the storm is falling apart. BUT. The same area where most of the convection originally fired is once again starting to produce convection that may be able to wrap around later on. NE quadrant seems to be where all the convection is firing.

You actually raise a good point regarding semantics and the ongoing question of STS v. TS. If you notice, the NHC plot chart has "S" for storm but it could remain sub-tropical or go fully tropical. Theoretically, Beryl could develop Cat 1 hurricane force winds, but, still remain or be classified as a sub-tropical storm. It will depend (as far as NHC is concerned) on how the storm develops tomorrow.

I've thought about FSU in the past, but the out of state tuition was too much for me. However, I am more than happy to be studying Meteorology here at Texas A&M University. It is definitely where I should be right now. I'm still considering FSU for grad school though, so maybe I'll run into some of y'all there someday. :P